<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>JS04</title>
        <script src="my.js"></script>
        <script>

          
          $(function(){

            $('div')
              .css({
                width:'50px',
                height:'50px',
                border:'1px solid blue',
                margin:'10px',
                borderRadius:'25px'
              })
              .on({
                mouseover(){
                  $(this).css({backgroundColor:'red'});
                },
                mouseout(){
                  $(this).css({background:'transparent'});
                }
              })
              .click(function(){
                alert(this.innerHTML);
              })
          });


            
        </script>
    
    </head>
    <body>

      <div>1</div>
      <div>2</div>
      <div>3</div>
      <div>4</div>
      <div>5</div>
      <div></div>
      <div></div>
      <div></div>
      <div></div>
      <div></div>
      <div></div>
      <div></div>
      
      

      


    </body>


</html>